Allow the bootstrap binary of GN (the one in TEMPDIR) to build and run on FreeBSD.

tools/gn/bootstrap/bootstrap.py

Index: tools/gn/bootstrap/bootstrap.py
diff --git a/tools/gn/bootstrap/bootstrap.py b/tools/gn/bootstrap/bootstrap.py
index 6ac7ac12b74e6461417fa5706322a26f5335699d..f6f2f977fa1bb26f2aa6eb38328b8bb2fb334e67 100755
--- a/tools/gn/bootstrap/bootstrap.py
+++ b/tools/gn/bootstrap/bootstrap.py
@@ -26,6 +26,8 @@ SRC_ROOT = os.path.dirname(os.path.dirname(GN_ROOT))
 def is_linux():
   return sys.platform.startswith('linux')
 
+def is_freebsd():
+  return sys.platform.startswith('freebsd')
 
 def check_call(cmd, **kwargs):
   logging.debug('Running: %s', ' '.join(cmd))
@@ -202,11 +204,10 @@ def write_ninja(path):
       'base/vlog.cc',
   ])
 
-  if is_linux():
+  if is_linux() or is_freebsd():
     static_libraries['libevent'] = {
         'sources': [
             'third_party/libevent/buffer.c',
-            'third_party/libevent/epoll.c',
             'third_party/libevent/evbuffer.c',
             'third_party/libevent/evdns.c',
             'third_party/libevent/event.c',
@@ -221,9 +222,7 @@ def write_ninja(path):
             'third_party/libevent/strlcpy.c',
         ],
         'tool': 'cc',
-        'include_dirs': [
-            os.path.join(SRC_ROOT, 'third_party', 'libevent', 'linux')
-         ],
+        'include_dirs': [],
         'cflags': cflags + ['-DHAVE_CONFIG_H'],
     }
     static_libraries['xdg_user_dirs'] = {
@@ -244,13 +243,8 @@ def write_ninja(path):
         'base/message_loop/message_pump_libevent.cc',
         'base/nix/xdg_util.cc',
         'base/posix/file_descriptor_shuffle.cc',
-        'base/process/internal_linux.cc',
         'base/process/kill_posix.cc',
-        'base/process/process_handle_linux.cc',
         'base/process/process_handle_posix.cc',
-        'base/process/process_iterator_linux.cc',
-        'base/process/process_linux.cc',
-        'base/process/process_metrics_linux.cc',
         'base/process/process_metrics_posix.cc',
         'base/process/process_posix.cc',
         'base/safe_strerror_posix.cc',
@@ -258,14 +252,43 @@ def write_ninja(path):
         'base/synchronization/condition_variable_posix.cc',
         'base/synchronization/lock_impl_posix.cc',
         'base/synchronization/waitable_event_posix.cc',
-        'base/sys_info_linux.cc',
         'base/sys_info_posix.cc',
-        'base/threading/platform_thread_linux.cc',
         'base/threading/platform_thread_posix.cc',
         'base/threading/thread_local_posix.cc',
         'base/threading/thread_local_storage_posix.cc',
         'base/time/time_posix.cc',
     ])
+    if is_linux():
+      static_libraries['base']['sources'].extend([
+          'base/process/internal_linux.cc',
+          'base/process/process_handle_linux.cc',
+          'base/process/process_iterator_linux.cc',
+          'base/process/process_linux.cc',
+          'base/process/process_metrics_linux.cc',
+          'base/sys_info_linux.cc',
+          'base/threading/platform_thread_linux.cc',
+      ])
+      static_libraries['libevent']['sources'].extend([
+          'third_party/libevent/epoll.c',
+      ])
+      static_libraries['libevent']['include_dirs'].extend([
+          os.path.join(SRC_ROOT, 'third_party', 'libevent', 'linux')
+      ])
+    elif is_freebsd():
+      static_libraries['base']['sources'].extend([
+          'base/process/process_handle_freebsd.cc',
+          'base/process/process_iterator_freebsd.cc',
+          'base/process/process_metrics_freebsd.cc',
+          'base/sys_info_freebsd.cc',
+          'base/threading/platform_thread_freebsd.cc',
+      ])
+      static_libraries['libevent']['sources'].extend([
+          'third_party/libevent/kqueue.c',
+      ])
+      static_libraries['libevent']['include_dirs'].extend([
+          os.path.join(SRC_ROOT, 'third_party', 'libevent', 'freebsd')
+      ])
+      ldflags.extend(['-lexecinfo'])
 
     cflags.extend(['-O2', '-pthread', '-pipe'])